CHAPTER III.

CONNECTIONS AND WIRING.

Fig. 20 shows how to connect up an automatic burner with two pushes; thus one can be downstairs in the hall and the other upstairs, allowing one to either extinguish or light the gas from either place. The value of this arrangement is obvious; it allows one to light up the hall before descending at night, or to put out the gas after one is safely upstairs. Again, an automatic burner can be put in the cellar and lighted and extinguished from the head of the cellar-stairs, saving matches and danger of fire.

Fig. 21 shows the connections of one automatic burner and two pendant or rachet burners. _P P_ are the pendent burners, _A_ the automatic burner, _C_ the primary coil, _S_ the buttons which control the automatic burner, _M M M_ the cells of battery, of which there should be at least four, if not six. A low-resistance cell must be used here, as before mentioned, one that gives not _less_ than 5 amperes on short circuit. It will be seen here that one side of the battery is connected to ground (or gas pipe), the circuit being completed owing to the burners being themselves screwed into the gas pipe. Care must be taken, however, to first see that no insulating bushings have been used at the gas fixtures, as is done in wiring for electric light. In this case a double circuit will have to be run.

In wiring up an automatic burner with two electro-magnets, two wires are run, one from the black button and one from the white button on push-plate. Most burners have binding posts inside the case, the wires running through a rubber-bushed hole in the base. One of the greatest defects in the old style automatics arose from the two binding posts being fixed on a hard rubber block, which was held by one screw to the burner top. This screw got loose at times and the block used to twist, making it hard to tighten the wires. But improvements have been made in this direction, the later burners having a block with a projection which engages in a hole in the cover, and is held by two screws.

If the push has been set in place, and all wiring done, connect up the burner, first ascertaining to which binding post the two wires run. This is done by having one button pressed, the lighting (white) one, for example, and then touching the binding post with either wire. The lighting armature will buzz violently when touched, whereas the extinguishing one only strikes once when contact is made. When only one person is working, a pin can be wedged in the push so as to keep the circuit closed.

In setting up these burners care must be taken not to bend contacts or alter adjustments, and absolute precaution is necessary that no wires touch where uninsulated. A cause of trouble is a dirty burner which does not allow the gas to strike the contact spark. The collar carrying the second contact may shift, or perhaps become short-circuited in a pendant or ratchet burner; a strip of asbestos will remedy this.

BURNER DISTRIBUTION.

In fitting a house with electric lighting burners, the question of selection is best solved as follows: For the main hall and foot of the cellar-stairs, use the automatic burner. For other hallways, dining-room, drawing-room, and bathroom use ratchet burners which turn on and light gas when chain is pulled. For bedrooms use plain pendant burners; automatics and ratchets add an element of danger, in that they may not turn off gas, or may leak. Most of this type on the market are as reliable as it is possible to make them, but still accidents will happen.

The frontispiece shows a diagram of the wiring in a dwelling house of medium size, dividing it into three sections, each section being controlled by a switch--either a hand switch or one of the automatic cut-out switches elsewhere described. The burners are distributed as follows:

No. 1 in the front cellar, pendant or ratchet.

No. 2 in the rear cellar at foot of stairway is an automatic burner controlled from kitchen above.

Nos. 3 and 4 ratchet burners on chandeliers in drawing-room and dining-room.

No. 5 ratchet or pendant in kitchen.

No. 6 pendant in bedroom.

No. 7 ratchet or pendant in bathroom.

No. 8 pendant in bedroom.

No. 9 pendant in bedroom.

Nos. 10, 11, and 12 pendants in bedroom.

No. 13 automatic burner in hallway operated from pushes in lower and in upper hallways.

The articles required for this job are as follows:

Two automatic burners.

Three gas lighting push-buttons and bases. Pendant and ratchet burners according to number of lights in rooms.

Six cells--open circuit battery.

One three-lever switch.

One 8 or 10 inch spark coil.

Three pounds No. 16 patent finish office wire.

Two ounces No. 24 gas-fixture wire.

One pound tinned 3/8" staples.

Few square inches tinfoil.

Small roll insulating tape.

Tools: 4-inch screwdriver, pocket knife, 4-1/2-inch side-cutting pliers, hammer, piece of sandpaper.

The simple section switch is shown enlarged in Fig. 22. The wires 1, 2, and 3 are from their respective circuits and terminate at the switch arms _A A A_. The wire from the battery _B_ and coil _C_ runs to _each_ switch-stud _S S S_. If trouble shows on the line, each circuit can be thrown off by moving its switch arm until the fault is located. If it is not found at once, and the battery is weak, (test each cell with an ordinary electric bell), open all the circuits until the battery is recuperated, and disconnect the battery wire from the switch. Then attach the battery wire to the bell and touch each switch lever with a wire from the other binding post of the bell. If there is a short circuit on any section, the bell will ring or tremble when the arm is touched.

On the contrary, if the burners fail to work and no sign of a short circuit can be thus obtained, it is evident that a wire is broken or a screw is loose.

To locate a break, connect up the bell as just described and attach the testing wire to the switch with all levers closed; this is actually putting the bell in series with the battery, coil, and ground. Then hunt for the break. Take a long piece of wire and fasten one end to a ground pipe. Then touch the other end to the circuit wire in the cellar as far as you can go, baring the insulation in spots, but carefully re-insulating it again. If there is no break in the cellar, the bell will ring loudly at each contact. Next, proceed to the next floor and repeat the operation, gradually working _away_ from the battery. As soon as you pass the break, the bell will fail to respond. Two persons here are better than one, as it may be necessary to go quite a distance from the bell before finding the trouble.

Fig. 23 shows details of the wiring from the hall light to the two push-buttons. A wire is run right down from the top push _T_, middle connection, past the lower push _L_, where a similar branch joins it, until it reaches the section switch. The lighting and extinguishing wires from the lower push run up and are joined on to the similar wires from the top push, which latter wires go directly through the floor and ceiling to the automatic burner _A_.

Fig. 24 is the detail of the wiring for the cellar automatic burner _A_, from the push _P_, and is so clearly shown as not to require further explanation.

The secret of success in gas-lighting work is careful wiring. The platinum tip of the vibrating rod is often bent, either by accidental blow or by the continual hammering against the tip on the collar. This often causes an open circuit when the lighting armature refuses to buzz. Again, soot will form, causing weak action owing to imperfect contact. Examine, adjust, and clean; here, as in all electrical work, contacts must be clean.

In general wiring, use weatherproof office wire, or, better still, well-made electric light wire. For ordinary house work No. 16 B. & S. gauge is preferable; smaller wire means higher resistance and less current at burner. For braided office wire, No. 16 runs about 95 feet to the pound, No. 18 about 135 feet to the pound. The cheaper grades of wire without the patent finish or extra insulation are not worth using; sooner or later trouble will ensue, and once a house is wired, it is no pleasant job to hunt trouble, especially if the wire was put on before the plaster. In modern buildings in large cities, the use of conduit tubes has become general, but the handling of these conduits comes more under the province of the electric-light wireman and less within the scope of these pages.

In wiring new wooden buildings do not draw wires too tight; the wood may expand and either break wire or cause a weakening of the insulation. In wiring before the plaster is put on, always leave a good length free, so it will not be covered up by the plasterers.

The wire used on the gas fixture is of a special kind, being made for the purpose. It is made in two sizes, No. 22 and No. 24 B. & S. gauge, and with three windings of cotton, three outer layers of cotton and one of silk, or three windings of cotton which is soaked in fireproof preparation, and then wound with silk.

As the piece used is generally short, these small sizes are sufficient in carrying capacity. After wiring up a fixture, this fine wire can be tied on to the pipes, etc., with thread, and a good coating or two of shellac varnish applied. When this is dry, the thread can be removed and the shellac will hold the wires on to the fixture. On no account finally connect up the battery to a circuit when shellacking the wire. Wait until the shellac is thoroughly dry and _hard_--at least half a day, if possible.

White lead is generally used at the joints where the burner screws into the fixture, but tinfoil wrapped round the joint will give good service. It prevents leaks and ensures a good contact.

The ground connection at the battery must be first-class; do not be content with just wrapping a few turns of wire around the pipe in the cellar (assuming the battery is in the cellar), but clean and scrape the pipe; clean at least two feet of the wire, wind it tightly and evenly on the pipe and _solder_ it. There is a pipe-clamp made which is clamped on the pipe and the wire attached to that, but it must be properly put on a clean surface.

WIRING FINISHED HOUSES.

In wiring finished houses, especially wooden ones, the wires can be run along skirting boards, and often pushed out of sight in the space between the floor and the skirting. This is quite permissible, as the wires, unlike electric-light wires, carry no dangerous current; but waterproof wire becomes preferable, as the water used in washing a floor will often creep under and rot the insulation. In going upstairs, wires can often be run in the fluting of a moulding along the stairway, and be quite inconspicuous; but wherever possible, fish the wires up inside the wall. The main thing to be considered in wiring is that the wires are large enough, well insulated, all joints well made and taped and put where there is no danger of injury. Rats have a habit of gnawing paraffin-coated insulation, and it is well to run such in metal tubes. In joining or splicing wires, do it in a thorough manner, and solder if possible. Never use the old bell-hanger joint--the one in which the ends of the wires are merely looped together. Strip insulation and scrape or sandpaper bright about three inches of each wire to be spliced. Then, placing the bare wires across each other about three-quarters of an inch from the insulation, tightly wind the loose bare ends of each around the bare inside portion of the one it is being spliced to. A touch of solder will prevent trouble from oxidation, after the adhesive tape has been wrapped on. Attention to details like these will often ensure the satisfactory working of the job.

A handy tool for gas-lighting wiring is shown in Fig. 25. One end is bored out to fit the small nuts on the ratchet and pendant burners, and the other is filed flat for use as a screwdriver.

A case may arise where there is electric light on the same chandelier as the gas lights, and that an insulating bushing has been screwed in between the fixture and the pipe. In this case it will be necessary to run two wires to each burner, the pipe common return being now unavailable. Another scheme is to interpose an insulating bushing under each burner; then the second or return wire need only be run from the burner to the gas pipe _outside_ the main bushing. But the local fire-insurance rules must first be consulted.

Most ceiling gas fixtures will admit of the fixture wire being run inside the brass shell, which makes a neater job. But the very best of insulation must be used, and great care be taken that it be not abraded. It should be shellacked or otherwise insulated before use. The electric-light fixture wires are admirable for use here if there is room.

For concealed work in a finished house, locate the position of the fixture under the floor of the room above by measuring both in the room where the fixture is and in the room above. Then cut out a piece of the floor, drill up from underneath through the fixture plaster-rose with a fine drill, and push the fixture wire up. The main wire can be laid under the carpet, or along the floor-crack in the upstairs room.

In wiring up wall-fixtures, push-buttons, etc., it is often possible to fish the wire up from the floor by punching a hole at the fixture and inserting a piece of chain (made for the purpose), attached to a long and stout thread. Then drill into the skirting near the floor plumb underneath the first hole and fish for the chain with a piece of wire having a hook on the end of it. Where fixtures have brass rosettes, these can be removed by (generally) unscrewing the fixture, _but first shut off the gas_ at the meter, or plug the hole; this may seem unnecessary advice, but experience warrants its being given. When the chain is fished out, a piece of wire can be attached to the thread and pulled through in turn. In most cases its point of exit at the fixture can be concealed by the rosette, through a hole in which it passes. Take care that the edges of this hole do not cut the insulation. Care must be taken at every step in gas-lighting wiring.

In wiring up a push-button, screw all wires tightly under their respective binding screws, and then cover wherever possible with adhesive tape. As the wires must be somewhat loose to allow of the connections being made at the back of the push-button at the wall, they will have to be carefully pushed into the hole, and if they are not tightly held by screws, trouble will result. It is a good plan, when using fine enough wire, to make a sort of eye at the end of the wire and pass the screw through this, instead of merely giving the wire end a turn around the screw and then driving the screw home. Of course washers should be used wherever an ordinary screw holds a bare wire.

AUTOMATIC BURNER OPERATED BY DOOR.

One of the uses to which an automatic burner can be put is in conjunction with an electric door-spring, lighting when the door is opened, but preferably extinguished by independent push. In this case, a form of trip spring should be used which would only make contact during a portion of the travel of door. Such a trip is shown in Fig. 26.

_A_ is automatic burner; _C_, the primary coil; _B_, the battery; _T_, a swinging trip piece of brass hinged in brass plate, _P_, which is screwed over the door in such manner that the door opening in direction of the arrow will cause the trip _T_ to strike against the spring _S_, and make contact. This spring is insulated from the plate _P_ by the hard rubber block _R_.

On the door being opened, the trip will make contact long enough to light the burner and will then fall back as the door passes. On shutting the door, the trip will be raised and will fall as the door passes, but will not make contact. Or, if so desired, it can be made to operate a second contact to extinguish the burner by fixing a second insulated spring so it will be pressed when the top of trip makes a downward movement--as when the door passes it in shutting.

Various applications of automatic burners in connection with burglar alarms will suggest themselves, but in these cases the utmost care must be taken that the apparatus is in good working order; failure to light might cause the room to be filled with gas, and serious results ensue.

For those persons who use gas stoves and are mechanically inclined, an arrangement of an alarm clock with an automatic burner will enable them to light up without getting out of bed, or perhaps even waking up.